The present activities of the Joint Research Centre (JRC), a Directorate General of the European Commission, in the field of monitoring sea-based oil pollution are described. The methodology used to process and interpret a massive set of satellite images (i.e., mosaics over all the European Seas), and the relevant legal framework are briefly introduced. Both the issues of accidental and deliberate oil discharges are addressed. The presentation then focuses on JRC experience acquired on the use of satellite images during the Prestige accident emergency. At that time, the JRC provided technical assistance on the interpretation of the satellite images to the EC Civil Protection Mechanism and interested EU Member States. In addition to this task, JRC is carrying out a systematic mapping of the illicit vessel discharges using mosaics of satellite images over all the European Seas. These maps and the associated statistics are repeated on an annual basis in order to assess its evolution. The results obtained for the Mediterranean and the Black Sea are of special interest due to the lack of a regular aerial surveillance as that in the North and in the Baltic Sea. This action helped to reveal for the first time what is the dimension of the oil pollution problem, thus stressing the need for more concerted international actions. Finally, a strategy to tackle this issue is presented. In this context, the need for additional research efforts involving the competent regional/national authorities and the importance of securing the role of space-borne sensors in support to aerial and naval means are outlined. The proposed strategy is based on the involvement of the end-users. Consequently, the JRC together with DG Environment has established a permanent Group of Experts on satellite monitoring of sea-based oil pollution.